Motion picture projecting machine



Feb. 9, 1932. R. A. CLAPP IOTION PICTURE PRQJECTING MACHINE Filed Dec. 10. 1927 4 Sheets$heet l Feb. 9, 1932.

R. A. CLAPP 1,844,561

MOTION PICTURE PROJECTING MACHINE Filed Dec. 10, 1927 4 Sheets-Sheet 2 I uan/or a orucg Feb. 9, 1932. R. A. CLAPP MOTION PICTURE PROJECTING MACHINE Filed Dec. 10, 1927 4 Sheets-Sheet 3 an b I77var Feb. 9, 1932. R. A. CLAPP MOTION PICTURE PROJECTINQMACHINE Filed Dec. 10. 192 4 Sheets-Sheet 4 Patented Feb. 9, 1932 UNITED STATES ROYAL A. CLALPP, OF BROOKLINE, MASSACHUSETTS MOTION PICTURE PROJEC'IING MACHINE Application filed December 10, 1927. Serial No. 239,175.

My present invention relates to machines for projecting pictures from continuous strips of films, otherwise known as moving picture projecting machines.

An important object of the present invention is to devise a machine which will have a minimum number of parts, and which will, therefore, be economical to manufacture, easy to assemble, and simple to operate. I Also, by reducing the number of parts uti lized in the construction and operation of the machine, a much lighter and more compact apparatus is produced than would otherwise be possible, enabling the same to be handled l more easily and to be utilized in installations where a larger machine would be unwieldy and impractical.

A further object of the present invention resides in the provision of means, utilized to advance the film in an intermittent motion,

which means will be provided with a slow start, a smooth acceleration, and a quick stop. I accomplish this desirable result by means of an improved Geneva movement, in which I substitute, for the four radial slots heretofore utilized, four curved slots or cam paths. In this manner, the pin or roller carried by the driving wheel Wlll enter said slots and engage the same on the curved side of each slot in succession. This will eliminate the annoying click which has heretofore been present in standard Geneva movements, and will also result in imparting a slow start to the rotation of the driven wheel, will give a. smooth acceleration thereto, while the driven wheel will be brought to an instant stop at the proper moment. In'this manner, I am enabled to increase the ratio of the driving and driven wheels from threeto one, to five or six to one, or to a still further de- .gree if desired. This ratio of five or sixto one is desirable, and in fact necessary in moving picture projectors, due to the speed with which the film must be fed through the camera. With the standard, Geneva movement it has heretofore been impossible to obtain this ratio resulting in fast feeding, except with the disadvantages above ex plained, but by my novel invention the same is accomplished in an extremely efficient manner.

A further feature of the present invention resides in so mounting the driven wheel of the Geneva movement, and the film feeding means controlled thereby, that any wear may be readily compensated for, thus increasing the life of the machine, and enabling a smooth, silent operation thereof at all times.

A further object of the invention is to 50 provide novel means for holding the film against the feeding sprockets. I accomplish this in such manner that only the outer edges of the film, adjacent to the perforations provided for the sprocket teeth, will be engaged by the holding means, leaving the center of the film unengaged, thus eliminating any scratching or marring of the film against the sprockets or other feeding means. I accomplish this desirable result by providing a pivoted frame or holder, at one end of which is pivotally mounted a shoe having thereon two upright yokes or pairs of webs having concave film and sprocket engaging surfaces. Into the yokes will project the teeth of the sprockets, the concave surfaces of the yokes or webs holding the film at each side of each line of perforations, but leaving the center of the film free of any holding devices. Also, by having the above mentioned shoe pivoted in the pivoted frame, the concave surfaces in said yokes or webs will follow the sprocket to any position to which it, together with the driven Geneva wheel, may be moved.

The above and further features of the in- 5 vention, details of construction, combinations of parts and advantages, will be hereinafter more fully pointed out and claimed.

Referring to the drawings, illustrating preferred embodiments of the present invention,

Fig. 1 is a side elevation of my novel moving picture projecting machine;

Fig. 2 is a cross-sectional view on the line 22 of Fig. 4;

Fig. 3 is a cross-sectional view on the line 3-3 of Fig. 4;

Fig. 4 is a cross-sectional view on the line 4-4 of Fig. 9;

Fig. 5 is a detail view, on an enlarged scale,

of my noveland improved Geneva movement;

Fig. 6 1S a cross-sectional View on the line 66 of Fig. 1;

'Fig. 7 is a cross-sectional view on the line 77 of Fig. 1; I

Fig. 8 is a perspective of the spring member to hold the film against the aperture;

Fig. 9 is a top plan view of the machine; and

Fig. 10 is a perspective view, on an enlarged scale, of my novel film holding device.

Referring now to the drawings for a detailed description of the machine and its operation, 11 designatesthe base of the machine, resting on legs 12 at one end, and on an adjustable screw 13 at the other end. This adjustable screw is controlled by a wing nut 14, or other suitable device, to raise or lower that end of the base on which is mounted the lamp house 15. Within the house 15 is located a bulb 16 and atone side of said house is provided an aperture 17 through which the light from the bulb 16 will project.

The base. 11 is provided with a vertical wall 18in which is positioned a condenser lens 19. Affi2red to the wall 18 by screws 20 is a housing121 within which is secured a reflector or mirror 22 fixed at anangle of 45 to the wall 18. The condenser 19 is alined with the aperture 17 in the lamp house 15, so that the light from the bulb will project through the condenser, striking against the reflector 22 and being deflected therefrom toward the front of the 'machine, through the apertures 23 and 24 in the plates 25 and 26 respectively,

and, thence through the lens 36 in the lens barrel 27 .to the screen on whichthe picture is to be displayed. The plate 25 has a flange 28 secured to the wall 18 by screws 29. Affixed to'the plate 26 byscrews 30 is a fiange 31 of a spring plate or member 32 illustrated in detail in Fig. 8. This spring 32 has a pair of legs 33 spanning the aperture 23, said spring being pressed against the inner sur face of the wall or plate 25, the legs 33 being then'bent at right angles as at 34 and provided at their ends with upturned lips 35 adapted to engage the inner surface of the pl'ate26 to providean increased pressure of the spring 32 against the inner surface of the wall 25. The plate26 is pivotally mounted on a pin 37 and is held in normal position, as in Fig. 3, by a spring 38. This spring 38 also assists in holding the spring 32 against the inner surface of the plate 25 in a firm manner. This structure just described, is known as the gate through which the film passes'during the projection of the characters on said film. AfliXed to the wall 18 are two arms, the upper arm 39 and the lower arm 40, thesearms being'adjustable on screws 'or'supports 41 and 42 respectively; The upper arm .39 carries a pin43 on which rotatably mounted areel with the perforations 51 in each side of the strip of film 45, thus providing a positive feed for said film. The film is then led upwardly, over the housing 21, and is'fed downwardly through the gate. The spring controlled, pivoted plate may be swung open for this operation, if desired. In order to provide for the intermittent feeding of the film through the gate, and prevent undue strains on the film, a free loop52 is left; above the gate, The spring 32 will insure that the film is maintained in a fiat,smooth position over the aperture 23. From the bottom of the gate the film is conducted over a sprocket 53 which is mounted on and secured to a-shaft 54. The

teeth 55. of thesprocket 53 will engage the perforations51 in the film, and thence the film is conducted back to the sprocket 48, andthereunder, the teeth '50 again holding the perforations 51 and feeding the film to the left, as shown in Fig. 3. A free loop 56 is sprocket 48, to prevent injury tothe film from the pull of the sprocket 48; From itsposition beneath thefsprocket 48 the film is then conducted over the pin 60 to thereel 57 provided, between the sprocket 53 and mounted on apin 58, said-reel beingheld in position bya locking arm 59. V r

In order to provi'le means to holdthe film against the sprocket 48'to insure meshing of theteeth 50 with the perforations 51 in the film, I pivotally mount, on the pins 47' and 60, frames .61 and 62 respectively, the upper frame 61carrying a roller 63 having apair of bifurcations therein to accommodate the teeth 50, while at the same timeholding the film 45 in closecontact with the sprocket 48. The lower frame 62 carries a similar bifurcated roller 64 tohold'the film against the sprocket 48 on its return passage. A spring 65 is connected to the outer ends of the two frames sprocket 53 upwardlyfa'ndon said-end of the frame I pivotally mount, on the pin 69a shoe 70, an aperture 71 being provided through theshoe 70 toaccommodate said pin. Projecting upwardly from the shoe 7 0 are two pairs of webs or yokes 72 and 73 having concaved surfaces 74 and 75, into which concavities the sprocket 53 will fit, the spaces between the pairs of webs 72 and 73 receiving the teeth 55, the concaved surfaces 74 and 75 only bearing against the film closely adjacent to the lines of perforations 51, thus leaving the center of the film free, with no pressure thereon. This particular form of film holding device is extremely eflicient and satisfactory, engaging the film over a lar e portion of the circumference of the sproc et 53, and I believe is novel with me. If desired, also, in place of the rolls 63 and 64, I may utilize the structure just described as the film holding means for the sprocket 48.

The shaft 49 is the main drive shaft of the projector, and on the outer end of this shaft is affixed a handle 76, a screw 77 preventing slippage of the handle on said shaft. The shaft 49 extends through a boss 78 on the wall 18, and through said wall, having aflixed on its outer end a gear 79, the shaft being e11- larged or headed as at 80 to retain said gear in place. The gear 79 meshes with a pinion 81 on the shaft 82, said shaft being mounted at one end in the wall 18 and at its other end in the raised boss or arm 83. Mounted on the shaft 82 also is a driving wheel 84 having thereon a pin or roller 85, and a circular boss 86, said boss being cut away as at 87 to provide a clearance for the projecting arms of the driven or star wheel 88 mounted on the shaft 54. These wheels 84 and 88 comprise, with the other features there-of to be de scribed, my novel Geneva movement.

Provided in the wheel 88 are four curved slots or cam paths 90. The convex surface 91 of the boss 86 engages the concave surface 92 between each pair of slots before the driving pin 85 is disengaged from the driven wheel 88, thus preventing the latter from rotating while the pin is moving around to engage the next successive slot. As the driv- 7 ing wheel 84 is moving in the direction of the arrow, Fig. 5, it will be appreciated that on entering any slot 90, said pin first engages the curved edge 93 of the slot 90, and, because of the curve of said edge, will not cause the sharp metallic click which has heretofore been present in this type of movement when utilizing radial slots. Thus, my novel construction will enable the driving pin 85 to impart to the wheel 88 a relatively slow start and a smooth acceleration, which start and acceleration are imparted, through the shaft 54, to the sprocket 53, and hence to the film 45, thus preventing injury or damage to the film through too quick a start, or jerk.

A further advantage of my improved Geneva movement is that I may construct the boss 86 and driven wheel 88 in the ratio of five to one or six to one, if desired, which thus increases the time that the film is idle as compared to the time that it is in motion, thus resulting in high speed with smooth thereof being requisite.

silent action, instead of noisy, jerky action.

I also preferably mount the shaft 54 in an aperture or bore 94 formed eccentrically in the sleeve 95, which sleeve has a reduced portion 96 extending through the wall 18 and boss 97, and on the sleeve 95 I afiix a lever or operating device 98, manipulation of the lever 98 rotating the sleeve 95 and hence the shaft 54, bringing the driven wheel 88 into closer contact with the boss 86, or moving it to a greater distance from said boss, as desired, thus providing a wide range of adjustment. Thus I am allowed to compensate for wear on the convex or concentric edge or face 91 and on the concaved surfaces 92, in a simple manner. Such variation of the position of the shaft 54 will of course slightly alter the position of the sprocket 53, but as the shoe 70 is pivoted in its frame, this shoe will follow any altered or adjusted position of said sprocket, and will still perform its film holding function with equal efiiciencv. In order to hold the sleeve 95 in adjusted position, I provide a set screw 99 extending through the boss 97 and engaging the reduced portion 96 of the sleeve 95, firmly holding the same.

Mounted on the shaft 82 also is a shutter 100 interposed between the aperture 17 in the lamp house 15 and the condenser lens 19, this shutter having a larger shutter vane 101 and two smaller flicker vanes 102, the function of these flicker vanes being well understood in the art and no detailed description The shutter vane 101 is adapted to intercept the light from the aperture 17 during the moment that the film is being fed past the apertures 23 and 24. Due to my improved Geneva movement, above described, I am enabled to reduce the size of these vanes to a considerable extent, which represents a. further advantage in this art. In order that the shutter 100 may rotate smoothly, I provide the same with a hub 103 and collar 104, fixed to the shaft 82 by a set screw 105 or the like, thus affording a broad bearing surface for the shutter element.

It is necessary, of course, to provide means to insure rewinding of the film on the reel 57, and I accomplish this by mounting on the shaft 49 a grooved disc 106, and on the shaft or pin 58, is another grooved disc 107, and running in the grooves of these two discs is a spring belt or drive 108, which form of drive insures against too-tight winding of the film on said reel 57, slippage of the spring 108 occurringwhen tension is placed thereon by the film 45.

The lens barrel 27 is mounted in the flange or arm 109 of the wall 18, and is slidable therein, being secured in adjusted or focused position by a set screw 110.

When assembling the gear 79 and grooved disc 106, I preferably unite these two articles, together with a spacing washer 111, by means of pins 112, position the same against the wall 18, and then insert the headed shaft 49. This method of assembly is optional and is illustrated herein as being asimple method of construction The operationof my novel projector is simple, and will be readily understood, being briefly summarized as follows:

The operator places the reel 44 on the pin I j 43, then conducts the film under the-pin 47 plate 26 against the tension of the spring 38.

lh-e film is then conducted downwardly under the sprocket 58, the teeth meshing with the perforations 51. Thence the film is led under the sprocket 48, leaving the free loop '56, theroller hholding the film against the under side of the sprocket, and thence over the pin to the reel 57. 'The projector is now ready to operate, and rotation 'of the handle 7 6 will cause rotation of the gear 7 9 and pinion 81. Rotation of'the pinion'will also cause rotation of the driving :wheel 8i of the Geneva movement, which in turn will control the rotationof the star or driven My invention is further described and defined in the form of claimas follows: 7

In a machine of the kind described, a film holding reel, agate comprising a pair of walls having .alined apertures'therein, means. to feed said film past said apertures, a spring plate positioned between said walls and fixed to one of said walls, said plate having a recess therein al-ined with said apertures, and a pair of legs projecting laterally from said spring plate adjacent to the open end of saidrecess, said legs spanning the space between said walls and bearing against the inner surface of one of said walls to provide an increased pressure of said spring plate against the in ner surface of the other of said walls, said legs having upturned ends to provide increased bearingof said legs against the inner surface of the first said wall.

In testimony whereof, I have signed my name to this specification.

. ROYAL A. CLAP P.

wheel 88 and :shaft 54:, together withthe sprocket 53, in'an intermittent movement, as,

above explained 1 Simultaneously the shutter. will be operated in synchronism with the feeding of the film through the gate, shutting off the light at the time of feeding of the film, as is usual. The projectedfilm will be rewound on the reel 57 through the medium of the springbelt or drive 108, whichwill also insure against too-tight winding of the film.

Due to the efficiency of my novelv Geneva movement, injury to the film through erking or the'like is eliminated, and the projector illustrated and described herein will function smoothly and efiiciently, at the high rate of speed required for these projectors.

lVh'e'n wear has occurred in the Geneva movement, manipulation of the lever 98 controlling-the eccentric sleeve r96 'will' adjust the relation of the wheels 84 and 88. I believe that my projector, as described herein is novel, and have therefore claimed the same broadly herein.

'The film holding mechanism, as particularr Nhile I have necessarily described my present invention somewhat in detail, it will be appreciated that I may vary the size, shape and arrangement of parts within reasonably ,Wide limits without departing from thespirit --ofqthe invention. .7 j a 

